Abstract: Objective To explore the value of 18F-FDG PET-CT in evaluating bronchial mucosa involvement in patients with
saroidosis. Methods A retrospective analysis was conducted among 6 sarcoidosis patients with and 14 patients without
bronchial mucosa involvement to collect the data including the standard uptake value (SUVMax/Mean) of 18F-FDG, serum
angiotensin converting enzyme (sACE), and proportion of lymphocytes and CD4+/CD8 + T lymphocyte ratio in bronchoalveolar
lavage fluid (BALF). Results The lung focal SUV (Max/Mean) was higher in patients with bronchial mucosa involvement than those
without (7.04±5.83/5.00±4.69 vs 5.68±3.66/3.82±2.39), but such differences were not statistically significant (P=0.565/0.495). The
SUV(Max/Mean) of the hilum of the lung and the mediastina lymph nodes were significantly higher in patients with bronchial
mucosa involvement (13.28±5.57/10.48±4.43 vs 6.20±1.77/4.52±1.43, P=0.0003/0.0002; 13.84±4.35/9.69±2.74 vs 7.16±2.52/5.28±1.77,
P=0.0004/0.0004). The level of sACE and CD4 +/CD8 + T lymphocyte ratio in BALF were also significantly higher in patients
with bronchial mucosa involvement (60.58±16.3 vs 49.16±13.3 IU/L, P=0.045; 7.30±5.0 vs 2.90±3.1, P=0.026). The proportion of
lymphocytes in BALF was comparable between the patients with and without bronchial mucosa involvement (44.10±10.3% vs
35.30 ± 12.5%, P=0.148). Conclusions For patients with saroidosis, 18F-FDG PET-CT is useful in evaluating bronchial mucosa
involvement, which is one of the key features of active sarcoidosis.